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基于Nginx XSendfile+SpringMVC进行文件下载

程序员文章站 2022-07-14 10:21:43
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源:http://abear.iteye.com/blog/1025942
评:
Java代码
@RequestMapping("/courseware/{id}")  
public void download(@PathVariable("id") String courseID, HttpServletResponse response) throws Exception { 

     ResourceFile file = coursewareService.downCoursewareFile(courseID); 
     response.setContentType(file.getType()); 
     response.setContentLength(file.contentLength()); 
     response.setHeader("Content-Disposition","attachment; filename=\"" + file.getFilename() +"\""); 
     //Reade File - > Write To response 
     FileCopyUtils.copy(file.getFile(), response.getOutputStream()); 
}


   @RequestMapping("/courseware/{id}")
   public void download(@PathVariable("id") String courseID, HttpServletResponse response) throws Exception {

        ResourceFile file = coursewareService.downCoursewareFile(courseID);
        response.setContentType(file.getType());
        response.setContentLength(file.contentLength());
        response.setHeader("Content-Disposition","attachment; filename=\"" + file.getFilename() +"\"");
        //Reade File - > Write To response
        FileCopyUtils.copy(file.getFile(), response.getOutputStream());
    }
    由于程序的IO都是调用系统底层IO进行文件操作,于是这种方式在read和write时系统都会进行两次内存拷贝(共四次)。linux 中引入的 sendfile 的实际就为了更好的解决这个问题,从而实现"零拷贝",大大提升文件下载速度。
    使用 sendfile() 提升网络文件发送性能
    RoR网站如何利用lighttpd的X-sendfile功能提升文件下载性能
 

    在apache,nginx,lighttpd等web服务器当中,都有sendfile feature。下面就对 nginx 上的XSendfile与SpringMVC文件下载及访问控制进行说明。我们这里的大体流程为:
     1.用户发起下载课件请求; (http://dl.mydomain.com/download/courseware/1)
     2.nginx截获到该(dl.mydomain.com)域名的请求;
     3.将其proxy_pass至应用服务器;
     4.应用服务器根据课件id获取文件存储路径等其它一些业务逻辑(如增加下载次数等);
     5.如果允许下载,则应用服务器通过setHeader -> X-Accel-Redirect 将需要下载的文件转发至nginx中);
     6.Nginx获取到header以sendfile方式从NFS读取文件并进行下载。

     其nginx中的配置为:
     在location中加入以下配置
      Conf代码
server { 
        listen 80; 
        server_name dl.mydomain.com; 

        location / { 
            proxy_pass  http://127.0.0.1:8080/;  #首先pass到应用服务器 
            proxy_redirect     off; 
            proxy_set_header   Host             $host; 
            proxy_set_header   X-Real-IP        $remote_addr; 
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for; 

            client_max_body_size       10m; 
            client_body_buffer_size    128k; 

            proxy_connect_timeout      90; 
            proxy_send_timeout         90; 
            proxy_read_timeout         90; 

            proxy_buffer_size          4k; 
            proxy_buffers              4 32k; 
            proxy_busy_buffers_size    64k; 
            proxy_temp_file_write_size 64k; 

        } 

        location /course/ {  
            charset utf-8; 
            alias       /nfs/files/; #文件的根目录(允许使用本地磁盘,NFS,NAS,NBD等) 
            internal; 
        } 
    }

server {
        listen 80;
        server_name dl.mydomain.com;

        location / {
            proxy_pass  http://127.0.0.1:8080/;  #首先pass到应用服务器
            proxy_redirect     off;
            proxy_set_header   Host             $host;
            proxy_set_header   X-Real-IP        $remote_addr;
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;

            client_max_body_size       10m;
            client_body_buffer_size    128k;

            proxy_connect_timeout      90;
            proxy_send_timeout         90;
            proxy_read_timeout         90;

            proxy_buffer_size          4k;
            proxy_buffers              4 32k;
            proxy_busy_buffers_size    64k;
            proxy_temp_file_write_size 64k;

        }

        location /course/ {
            charset utf-8;
            alias       /nfs/files/; #文件的根目录(允许使用本地磁盘,NFS,NAS,NBD等)
            internal;
        }
    }

    其Spring代码为:
    Java代码
package com.xxxx.portal.web; 

import java.io.IOException; 
import java.io.UnsupportedEncodingException; 

import javax.servlet.http.HttpServletResponse; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.stereotype.Controller; 
import org.springframework.web.bind.annotation.PathVariable; 
import org.springframework.web.bind.annotation.RequestMapping; 

import com.xxxx.core.io.ResourceFile; 
import com.xxxx.portal.services.CoursewareService; 

/**
* File download controller, provide courseware download or other files. <br>
* <br>
* <i> download a course URL e.g:<br>
* http://dl.mydomain.com/download/courseware/1 </i>

* @author denger
*/
@Controller
@RequestMapping("/download/*") 
public class DownloadController { 

    private CoursewareService coursewareService; 
     
    protected static final String DEFAULT_FILE_ENCODING = "ISO-8859-1"; 

    /** 
     * Under the courseware id to download the file. 
     *  
     * @param courseID The course id. 
     * @throws IOException  
     */ 
    @RequestMapping("/courseware/{id}") 
    public void downCourseware(@PathVariable("id") String courseID, final HttpServletResponse response) throws IOException { 
        ResourceFile file = coursewareService.downCoursewareFile(courseID); 
        if (file != null && file.exists()){ 
            // redirect file to x-accel-Redirect  
            xAccelRedirectFile(file, response); 

        } else { // If not found resource file, send the 404 code 
            response.sendError(404); 
        } 
    } 

    protected void xAccelRedirectFile(ResourceFile file, HttpServletResponse response)  
        throws IOException { 
        String encoding = response.getCharacterEncoding(); 

        response.setHeader("Content-Type", "application/octet-stream"); 
        //这里获取到文件的相对路径。其中 /course/ 为虚拟路径,主要用于nginx中进行拦截包含了/course/ 的URL, 并进行文件下载。 
        //在以上nginx配置的第二个location 中同样也设置了 /course/,实际的文件下载路径并不会包含 /course/ 
        //当然,如果希望包含的话可以将以上的 alias 改为 root 即可。 
        response.setHeader("X-Accel-Redirect", "/course/"
                + toPathEncoding(encoding, file.getRelativePath())); 
        response.setHeader("X-Accel-Charset", "utf-8"); 

        response.setHeader("Content-Disposition", "attachment; filename="
                + toPathEncoding(encoding, file.getFilename())); 
        response.setContentLength((int) file.contentLength()); 
    } 

    //如果存在中文文件名或中文路径需要对其进行编码成 iSO-8859-1 
    //否则会导致 nginx无法找到文件及弹出的文件下载框也会乱码 
    private String toPathEncoding(String origEncoding, String fileName) throws UnsupportedEncodingException{ 
        return new String(fileName.getBytes(origEncoding), DEFAULT_FILE_ENCODING); 
    } 

    @Autowired
    public void setCoursewareService(CoursewareService coursewareService) { 
        this.coursewareService = coursewareService; 
    } 
}

package com.xxxx.portal.web;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

import com.xxxx.core.io.ResourceFile;
import com.xxxx.portal.services.CoursewareService;

/**
* File download controller, provide courseware download or other files. <br>
* <br>
* <i> download a course URL e.g:<br>
* http://dl.mydomain.com/download/courseware/1 </i>
*
* @author denger
*/
@Controller
@RequestMapping("/download/*")
public class DownloadController {

private CoursewareService coursewareService;

protected static final String DEFAULT_FILE_ENCODING = "ISO-8859-1";

/**
* Under the courseware id to download the file.
*
* @param courseID The course id.
* @throws IOException
*/
@RequestMapping("/courseware/{id}")
public void downCourseware(@PathVariable("id") String courseID, final HttpServletResponse response) throws IOException {
ResourceFile file = coursewareService.downCoursewareFile(courseID);
if (file != null && file.exists()){
// redirect file to x-accel-Redirect
xAccelRedirectFile(file, response);

} else { // If not found resource file, send the 404 code
response.sendError(404);
}
}

protected void xAccelRedirectFile(ResourceFile file, HttpServletResponse response)
throws IOException {
String encoding = response.getCharacterEncoding();

response.setHeader("Content-Type", "application/octet-stream");
        //这里获取到文件的相对路径。其中 /course/ 为虚拟路径,主要用于nginx中进行拦截包含了/course/ 的URL, 并进行文件下载。
        //在以上nginx配置的第二个location 中同样也设置了 /course/,实际的文件下载路径并不会包含 /course/
        //当然,如果希望包含的话可以将以上的 alias 改为 root 即可。
response.setHeader("X-Accel-Redirect", "/course/"
+ toPathEncoding(encoding, file.getRelativePath()));
response.setHeader("X-Accel-Charset", "utf-8");

response.setHeader("Content-Disposition", "attachment; filename="
+ toPathEncoding(encoding, file.getFilename()));
response.setContentLength((int) file.contentLength());
}

    //如果存在中文文件名或中文路径需要对其进行编码成 iSO-8859-1
    //否则会导致 nginx无法找到文件及弹出的文件下载框也会乱码
private String toPathEncoding(String origEncoding, String fileName) throws UnsupportedEncodingException{
return new String(fileName.getBytes(origEncoding), DEFAULT_FILE_ENCODING);
}

@Autowired
public void setCoursewareService(CoursewareService coursewareService) {
this.coursewareService = coursewareService;
}
}